The ongoing effect of diabetes during pregnancy and the impact on infants
The Lancet Regional Health - Western Pacific
Background: Early-life risk factors, including maternal hyperglycaemia and birthweight, are thought to contribute to the high burden of cardiometabolic disease experienced by Indigenous populations. We examined rates of pre-existing diabetes in pregnancy, gestational diabetes mellitus (GDM) and extremes of birthweight over three decades in the Northern Territory (NT) of Australia. Methods: We performed a retrospective cohort analysis of the NT Perinatal Data Collection from 1987 to 2016, including all births > 20 weeks gestation, stratified by maternal Aboriginal identification. Key out- comes were annual rates of pre-existing diabetes, GDM, small-for-gestational-age, large-for-gestational- age, low birthweight ( < 2500 g), and high birthweight ( > 40 0 0 g). Logistic regression was used to assess trends and interactions. Findings: 109 349 babies were born to 64 877 mothers, 36% of whom identified as Aboriginal ethnicity. Among Aboriginal women, rates of GDM and pre-existing diabetes, respectively, were 3 ·4% and 0 ·6% in 1987 and rose to 13% and 5 ·7% in 2016 (both trends p < 0 ·001). Among non-Aboriginal women, rates of GDM increased from 1 ·9% in 1987 to 11% in 2016 ( p < 0 ·001), while pre-existing diabetes was uncommon ( ≤ 0 ·7% throughout). Rates of small-for-gestational-age decreased, while rates of large-for-gestational- age and high birthweight increased in both groups (all trends p < 0 ·001). Multivariable modelling sug- gests that hyperglycaemia was largely responsible for the growing rate of large-for-gestational-age births among Aboriginal women.